Transmission system for transmitting G3 facsimile signals and compressed speech signals

• US 5,323,398 A
• Filed: 10/23/1992
• Issued: 06/21/1994
• Est. Priority Date: 10/24/1991
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Wake, Yasuhiro, Usuki, Katsunori
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Jung, Min
• Application Number:
  US07/966,132
• Time in Patent Office: 606 Days
• Field of Search: 370/110.1, 370/112, 370/94.1, 370/94.2, 379/100, 358/434, 358/438
• US Class Current: 370/467
• CPC Class Codes: H04M 11/068 using time division multiplex techniques; integrated services digital networks H04Q11/0428
• CPC Class Codes: H04N 1/32704 Establishing a communication with one of a facsimile and another telecommunication apparatus sharing a single line
• CPC Class Codes: H04N 1/32708 Telephone
• CPC Class Codes: H04N 1/32715 Detecting

Abstract

A speech signal coding system including a speech signal encoder for dividing received speech signals into a plurality of frames each having a predetermined time interval and for converting the speech signals into digital speech parameters. The system includes a multiplexer for multiplexing the output digital data from the speech signal encoder into a predetermined frame format; a control frame generator for generating, in response to an inputted facsimile signal, a control frame having speech data frame configuration for identifying a facsimile signal identification data indicating the input signal as the facsimile signal. A facsimile signal demodulator converts the facsimile signal into digital data and a bit-synchronous multiplexer multiplexes the digital data. An output device outputs the speech data frame of the multiplexer to a digital transmission line and further outputs, when a facsimile signal is input, the control frame and facsimile data multiplexed as the bit synchronous data onto the digital transmission line.

Claims

1. A speech signal coding system comprising a speech signal encoder for dividing input speech signals into a plurality of frames each having a predetermined time interval and for converting said speech signals into digital speech parameters, a multiplexer for multiplexing digital data being outputted from said speech signal encoder into a predetermined frame format, a control frame generator for generating, in response to an input of a facsimile signal, a control frame having a speech data frame configuration for indentifying a facsimile signal identification data indicating said input signal as the facsimile signal, a facsimile signal demodulator for converting said facsimile signal into digital data, a bit synchronous multiplexer for multiplexing said digital data converted by said facsimile signal demodulator as bit synchronous data, and output means for outputting, when a speech signal is input, a speech data frame as an output of said multiplexer to a digital transmission line, and outputting, when the facsimile signal is input, said control frame followed by facsimile data multiplexed as said bit synchronous data to said digital transmission line.

2. A speech signal coding and decoding system comprising:

a speech signal coding system including a speech signal encoder for dividing inputted speech signals into a plurality of frames each having a predetermined time interval and for converting said speech signals into digital speech parameters, a multiplexer for multiplexing digital data outputted from said speech signal encoder into a predetermined frame format, a control frame generator for generating, in response to the input of a facsimile signal, a control frame having a speech data frame configuration for identifying a facsimile signal identification data indicating said input signal as the facsimile signal, a facsimile signal demodulator for converting said facsimile signal into digital data, a bit synchronous multiplexer for multiplexing said digital data converted by said facsimile signal demodulator as bit synchronous data, and output means for outputting, when a speech signal is input, a speech data frame as an output of said multiplexer to a digital transmission line, and outputting, when the facsimile signal is input, said control frame followed by facsimile data multiplexed as said bit synchronous data to said digital transmission line, and

a speech signal decoding system including a frame sync signal detector for detecting a frame sync signal in data received from said digital transmission line, a speech signal decoder for reproducing the original speech signal by using said speech parameters, when said received data is a speech data frame including speech parameters, processing means for processing, when said received data is said control frame having the speech data frame configuration, the received data following said control frame as bit synchronous data, and a facsimile data modulator for modulating the output of said processing means into a modem signal.

3. A speech signal coding and decoding system comprising:

transmitting coded speech signals as a speech frame when an input signal is speech signals;

transmitting a G3 facsimile data as a bit synchronous data after transmission of a G3 control frame having the same construction as that of the speech frame when said input signal is G3 facsimile signal; and

decoding the transmitted data of said coded speech signal data and G3 facsimile data based upon said G3 control frame.